What You Always Wanted To Know About The Kinetic Energy Damage To The WTC Towers, But Were Afraid To Ask:

"The buildings have been investigated and found to be safe in an assumed collision with a large jet airliner (Boeing 707 - DC 8) traveling at 600 miles per hour. Analysis indicates that such collision would result only in local damage which would not cause collapse or substantial damage to the building and would not endanger the lives and safety of occupants not in the immediate area of impact." Appendix A, NISTNCSTAR1-2, April 26, 2006 update.

"Our analysis indicated the biggest problem would be the fact that all the fuel (from the airplane) would dump into the building. There would be a horrendous fire. A lot of people would be killed," he said. "The building structure would still be there." John Skilling, Lead Structural Engineer for the WTC, The Seattle Times, February 27, 1993.

Kinetic Energy Calculations of Flight 11 and Flight 175 Impacts..........................

Considering the damage

the buildings performed rather well.

The insulation and firewalls, for the most part, held. There is little evidence of the fire spreading or jumping floors, after the initial impact and explosion. As a matter of fact, a number of the fires had burnt themselves out and did not spread.

71 billion joules!!!

That's 17 tons of TNT. Looks like you forgot to convert km/hr to m/s.

17 tons of TNT is bigger than a MOAB.

The design of the WTC towers was specified to withstand (at least) an impact energy of 4092 MJ, 12% greater than Flight 175's impact energy and 42% greater than Flight 11's impact energy.

Converting km/hr to m/s.

Thanks for the correction!